This invention relates to a cross-feed facing head structure and, more specifically, to a cross-feed facing head in which a slide is moved transversely of a rotating housing by means of an axially movable drawbar.
Cross-feed facing heads or generating heads have been known in the past in which a slide is caused to move transversely of a housing with respect to the axis of rotation by means of a drawbar and examples of such systems can be found in U.S. Pat. Nos. 4,033,207 and 4,040,315. Usually, four different basic actuating mechanisms are used for translating the axial movement of the drawbar into the transverse movement of the slide and these include (a) a rack and pinion mechanism, (b) a bell crank mechanism, (c) an inclined cam mechanism and (d) a helical spline mechanism. None of these is an ideal system, but the helical spline mechanism has some special advantages in terms of smoothness of operation. However, even with the helical spline it is difficult to form female gear teeth to mate smoothly with the helical spline for translating axial movement of the drawbar into rotary motion, and it also requires tremendous force to convert the rotary motion into a motion for transversely moving slides, due to the large mass of the slides.
It is the object of the present invention to provide an improved helical spline system for actuating a crossfeed facing head requiring minimum actuating forces.